Phylogenetic relationships of the Antarctic euphausiids inhabiting the Ross Sea and the adjacent regions of Southern Ocean

• Main Authors: GIORDANO, Daniela, RINELLI, Paola, RUSSO, Aniello, SALA, Antonello, AZZALI, Massimo, LA SPADA, Gina, GIULIANO, Laura, CRISAFI, Ermanno, DE DOMENICO, Elena, YAKIMOV, Michail
• Format: Text
• Language: unknown
• Published: Station Biologique de Roscoff (SBR) 2011
• Subjects: Antarctic; Ross Sea; Southern Ocean; The Antarctic; Antarc*; Antarctic Krill; Euphausia superba
• Online Access: https://dx.doi.org/10.21411/cbm.a.e65e7745; http://application.sb-roscoff.fr/cbm/doi/10.21411/CBM.A.E65E7745

Ross Sea supports a large concentration of Antarctic krill (Euphausia superba Dana, 1850) and Ice krill (Euphausia crystallorophias Holt & Tattersal, 1906) that have a great ecological significance (Azzali & Kalinowski, 1999; Sala et al., 2002). The aim of this study was to further our understanding of the distribution and phylogeny of krill species that were collected in the Ross Sea during the XIX PNRA expedition. Krill from 33 net samples were examined by sequencing parts of two mitochondrial genes; 530 bp of the gene 16S from a total of 20 specimens and 983 bp of NADH from 200 specimens. BIO-ENV analysis showed that the distribution of these species correlated best with water temperature than bottom depth and the ice presence. AMOVA analysis, conducted using the NADH data among geographic populations, revealed no significant differences of nucleotide diversity within the two Euphausia species: E. superba (n = 100, h = 0.97533 ± 0.0472, pi = 0.53433 ± 0.17212), E. crystallorophias (n = 100, h = 0.81762 ± 0.07431, pi = 0.48578 ± 0.46825). Most of the variability is associated with individuals and may depend on the high polymorphism of the species. AMOVA analysis between net samples showed no significant differences in all species.